Prepare the chicken liver. Chop the chicken livers, and set aside. Once all chicken livers are chopped, wash under running water, then strain. Set aside.
Cook the Chicken Liver Adobo. Heat up a pan under medium fire, and add 3 tbsp of cooking oil. Sauté the finely diced onions and minced garlic for 30 seconds, or until onions are translucent and soft. Add the diced tomatoes, and season with a generous pinch of salt and ground black pepper. Cook the tomatoes until the juice comes out, and tomatoes soften. Add the washed and chopped chicken liver. Mix for 15 seconds, then pour the vinegar all over the chicken liver. Do not stir. Let it simmer for 30 seconds under low fire, without covering the pan. This will let the acidity of the vinegar evaporate. This will also help in removing the unwanted smell and after-taste of liver. After 30 seconds, mix the chicken liver. Add the soy sauce and ground black pepper, and mix it well. Add the bay leaf, cover the pan, and let it simmer for another minute. Remove the cover and add the bell pepper, and mix again for another 15 seconds. Let it simmer for another 30 seconds. Add the green chilis and kalamansi juice towards the end. Mix for 30 seconds, then turn off the heat.
Serve! Transfer the Chicken Liver Adobo to a serving dish, and garnish with more chilis if you want it spicier. Serve and enjoy while hot!